The invention relates to a data carrier for the contactless communication with a communication station, which data carrier comprises a first carrier layer and a second carrier layer and an adhesive layer situated between said two carrier layers for holding together the two carrier layers, as well as an integrated circuit located in a given position between one of the two carrier layers and the adhesive layer, which integrated circuit comprises circuit transmission means which are in communicative connection with transmission means at the first carrier layer.
A data carrier with the construction described in the opening paragraph above is marketed by applicant and is accordingly known. The known data carrier comprises a bottom layer as the first carrier layer and a covering layer as the second carrier layer. Two capacitor plates of large surface area in relation to the surface area of the bottom layer are provided at the bottom layer as the first transmission means, by which a contactless communication with a communication station can be achieved. A respective capacitor plate also provided on the bottom layer and of small surface area in relation to the surface area of the bottom layer is connected to each of the two large-area capacitor plates provided at the bottom layer. A communication with two circuit capacitor plates provided as circuit transmission means at the integrated circuit is possible by means of these two small-area capacitor plates. The integrated circuit in the known data carrier is connected to the bottom layer in a mechanically stable manner by means of a separate, small-area adhesive joint which is provided in the region of the two small-area capacitor plates, and is accordingly retained in a given position reserved for the integrated circuit in the known data carrier. The adhesive layer lying between the bottom layer and the covering layer here supports the retention of the integrated circuit in the position reserved for it.
It is a disadvantage of the known data carrier that a partial application of an adhesive for fastening the integrated circuit is necessary for realizing the adhesive joint envisaged between the bottom layer and the integrated circuit, which constitutes an additional process step in the manufacture of the data carrier. An exact positioning of the adhesive application means with respect to the bottom layer of the data carrier is necessary here for the partial application of the adhesive in the manufacture of the data carrier, as is an exact positioning of the integrated circuit with respect to the bottom layer of the data carrier, which necessitates a high accuracy and accordingly a comparatively high expenditure. Furthermore, an exact dispensing of the quantity of adhesive to be partially provided must be carried out in the manufacture of the known data carrier, which again involves a considerable expenditure. Overall, therefore, the manufacture of the adhesive joint provided between the integrated circuit and the bottom layer requires a considerable expenditure, which is disadvantageous and leads to a high manufacturing cost.
Reference may also be made to the patent document WO 99/65002 A1 in connection with a data carrier with the construction as described in the opening paragraph. Mention may be made here in particular also of the construction of a known data carrier as shown in FIG. 14 and the construction of a known data carrier as shown in FIG. 2 of this patent document.
The invention has for its object to avoid the disadvantageous situations described above and to realize improved data carriers which can be manufactured in a simpler and less expensive manner.
To achieve the object indicated above, inventive features are provided in a data carrier according to the invention such that a data carrier according to the invention can be characterized as follows:
a data carrier which is constructed for contactless communication with a communication station, and which comprises a first carrier layer and a second carrier layer, and which comprises an adhesive layer located between the first carrier layer and the second carrier layer for holding said two carrier layers together, and which comprises an integrated circuit lying in a given position between one of the two carrier layers and the adhesive layer, which integrated circuit comprises circuit transmission means, wherein first transmission means are connected to the first carrier layer, the first transmission means bear at least substantially on the adhesive layer and by means of the first transmission means a contactless communication of the data carrier with a communication station can be implemented, and wherein second transmission means are connected to the first carrier layer, the second transmission means are connected to the first transmission means with electrical conduction and are in operational connection with the circuit transmission means for communication purposes, and wherein the final, mechanically stable retention of the integrated circuit in its given position is realized by means of the adhesive layer only.
A data carrier is realized through the provision of the features according to the invention in a constructionally very simple manner and by means which are simpler than those known from the prior art, in which data carrier the integrated circuit is retained exactly in the position designed for it in the data carrier in a reliable manner, but advantageously without a separate adhesive joint between the integrated circuit and the first carrier layer immediately adjoining the integrated circuit. It is advantageously achieved in a data carrier according to the invention, furthermore, that no process step for the partial application of an adhesive substance for fastening the integrated circuit to the first carrier layer is necessary in the manufacture of the data carrier, which constitutes a simplification of the manufacturing process. The advantage is furthermore achieved that, because a partially applied adhesive is not necessary in the manufacture of the data carrier according to the invention, it is also not necessary to position the integrated circuit, which is to be positioned and to be retained finally in a given position, in a particularly accurate manner during the manufacture of the data carrier. A further advantage is that the absence of a separate small-area adhesive joint between the integrated circuit and one of the two carrier layers of the data carrier means that the data carrier may be of a thinner overall construction.
In a data carrier according to the invention, the integrated circuit may be provided between the first carrier layer and the adhesive layer, in which case it is particularly advantageous if the adhesive layer is first provided over a large area of the second carrier layer before the data carrier is completed. It was found to be particularly advantageous in a data carrier according to the invention, however, if the integrated circuit lies between the adhesive layer and the second carrier layer. This provides the advantage that the adhesive layer may first be provided over a wide area on the first carrier layer in the manufacture of such a data carrier and may also be provided on the transmission means connected to the first carrier layer during this, whereupon the integrated circuit may be laid on the adhesive layer previously provided on the first carrier layer, so that the integrated circuit is retained in a simple and reliable manner in the position reserved for it already during manufacture.
The aspects mentioned above and further aspects of the invention will become apparent from the following description of embodiments and will be explained with reference to these embodiments.